Page 80 - Fall 2023 EDM Today

EDM Today Magazine EDM Today Magazine EDM Today Magazine

Unfortunately, based on the age of the Elox
machines, replacement hydraulic cylinders have a
long lead-time – typically about six weeks.
Your Elox 12-3816 has a 12” stroke cylinder –
see Figure 1. The cylinders are made by Sheffer.
It is part number 1345200. These are also
somewhat expensive. The cost in 2023 is
approximately $975.
EDM Today Magazine EDM Today Magazine EDM Today Magazine
We would recommend against trying to rebuild
the cylinder. Certainly, you can replace the seals,
but that does not repair the scoring in the rod.
You may slow the leak, but in most cases a seal
change will still result in oil dripping into the work
tank. The only sure way to stop a cylinder leak is
to replace the cylinder.
I have two recommendations:
Try to capture the leaking oil and prevent it from
getting into the work tank. If you do, it will buy you
some time to wait for a replacement cylinder to
arrive.
EDM Today Magazine EDM Today Magazine EDM Today Magazine
Another recommendation would be to consider
eliminating the hydraulic system altogether. The
Elox heads allow for an easy conversion to
servo motor driven heads. There are several
companies that make what are called electric
actuators – see Figure 2.

EDM Today Magazine EDM Today Magazine Figure 2 EDM Today Magazine

Figure 1
Electric Actuator
Elox 12-3816

The actuators are completely self-contained systems that include servo motor, ball screw, thrust bearings, brake, and
EDM Today Magazine EDM Today Magazine EDM Today Magazine
encoders. The actuator would mount on top of the head and connect to the platen using a rod extension. It can develop
a force similar to that of a hydraulic cylinder. This change offers several advantages:
• You eliminate all hydraulic maintenance.
• Actuators have a quicker response time and generally improve fi nishing performance.
• Actuators can achieve much higher speeds. Along with an external ram pulser, they add high-speed jump
fl ushing capability.
The cost of an electric actuator is quite a bit more expensive than a replacement cylinder.
But depending on how much the EDM is used, and the type of work done, it may pay for
itself with improved productivity.
Rick Martus
EDM Today Magazine
EDM Today Magazine EDM Today Magazine EDM Today, Fall 2023 Issue

78